A data acquisition device for analog quantities of a motor protector and a DCS system

Abstract

This utility model discloses a data acquisition device for analog signals from a motor protector and a DCS system, relating to the technical field of motor control. Specifically, it includes: a protector group, an analog data acquisition unit, a switch, and a DCS system connected in sequence; the protector group can be one or more; each protector group includes multiple motor protectors connected in sequence via serial ports using the MODBUS RTU communication protocol; the output of the protector group is connected to the analog data acquisition unit; the analog data acquisition unit is connected to the DCS system via the switch. This utility model utilizes the built-in serial port of the motor protector and employs the MODBUS RTU communication protocol to transmit the acquired motor current signal sequentially to the DCS system through the analog data acquisition unit and the switch, significantly reducing the number of cables, signal isolators, and analog input modules used, thereby effectively solving the problem of complex data acquisition device structure.

Description

Technical Field

[0001] This utility model relates to the technical field of electric motor control, and in particular to a data acquisition device for analog quantities of an electric motor protector and a DCS system. Background Technology

[0002] An electric motor protector is a device used to protect electric motors. Its main function is to monitor the motor's operating status and, in the event of various abnormal conditions such as overload, short circuit, grounding, undervoltage, overvoltage, leakage, three-phase imbalance, overheating, bearing wear, stator-rotor eccentricity, or winding aging, to cut off the power supply or issue a warning signal to prevent motor damage, thereby ensuring the safe and stable operation of electrical equipment. A DCS control system is a distributed control system composed of multiple computers and dedicated control software connected through a communication network. The DCS control system adopts the design principle of decentralized control and centralized management, integrating computer technology, control technology, communication technology, and graphic display technology. Functionally, it can be divided into process control layer, operation monitoring layer, and production management layer. Each layer has multiple computers connected through a communication network to form a distributed computer control system. It features safety and reliability, comprehensive functions, versatility and flexibility, and ease of operation, representing an advanced form of industrial process computer control.

[0003] Currently, in most projects, the communication between the motor protector and the DCS system is achieved through hard-wired connection. This allows the operating current of the motor equipment to be sent as a 4-20mA signal to the signal isolator via the analog output ports AO+ and AO-, and then connected to the AI ​​module of the DSC control system.

[0004] In existing technologies, motor protectors send current to the DCS through analog output ports AO+ and AO-. This approach requires an isolator between the motor protector and the DCS, and the analog signal must be processed by an AD conversion module before it can be used by the DCS. This method also necessitates one-to-one wiring for analog signal acquisition, resulting in a large number of terminal cabinets and isolator cabinets, leading to a complex structure. In large projects with numerous motors, the entire data acquisition device becomes even more complex. Utility Model Content

[0005] This invention provides a data acquisition device for analog quantities of motor protectors and DCS systems, which solves the problem of complex structure of existing data acquisition devices.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, this utility model provides a data acquisition device for analog quantities of motor protectors and DCS systems. The device includes: a group of protectors, an analog data acquisition device, a switch, and a DCS system connected in sequence.

[0008] The protector group may be one or more; each protector group includes multiple motor protectors that use the MODBUS RTU communication protocol and are connected sequentially via serial ports;

[0009] The output terminal of the protector group is connected to the analog data acquisition device;

[0010] The analog data acquisition device is connected to the DCS system through the switch.

[0011] In one possible implementation, within each of the protector groups, multiple motor protectors are connected sequentially via a daisy-chain wiring structure.

[0012] In one possible implementation, the serial port of the motor protector is an RS485 interface.

[0013] In one possible implementation, the analog data acquisition unit, the switch, and the DCS system are connected via Ethernet.

[0014] In one possible implementation, a maximum of 254 analog data acquisition devices are configured.

[0015] In one possible implementation, the analog data acquisition unit is a communication management unit with eight serial ports;

[0016] Each serial port of the communication management machine is connected in series with 10 of the motor protectors;

[0017] Each of the motor protectors has two RS485 interfaces.

[0018] In one possible implementation, the communication management unit is an ANet-2E8S1 intelligent communication management unit.

[0019] In one possible implementation, the motor protector is an ARD2F intelligent motor protector.

[0020] The motor protector and DCS system analog data acquisition device provided in this embodiment utilize the motor protector's built-in serial communication port and adopt the MODBUS RTU communication protocol to transmit the acquired motor current signal sequentially to the DCS system through the analog data acquisition device and the switch. This greatly reduces the number of cables, signal isolators, and analog input modules used. At the same time, the overall data acquisition device has a simple circuit, saves space in the DCS cabinet, reduces construction work, and is more economical. It also fully utilizes the data processing capabilities of the DCS system, thereby effectively solving the problem of complex data acquisition device structure. Attached Figure Description

[0021] Figure 1 A structural block diagram of a motor protector and a data acquisition device for analog quantities in a DCS system provided in this embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the overall structure of a motor protector and a data acquisition device for analog quantities in a DCS system provided in this embodiment of the present invention;

[0023] Figure labels and descriptions:

[0024] 1. Protector group; 11. Motor protector; 2. Analog data acquisition unit; 3. Switch; 4. DCS system. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, the use of "based on" or "according to" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" or "according to" one or more of the stated conditions or values ​​may in practice be based on additional conditions or beyond the stated values.

[0027] In existing technologies, motor protectors send current to the DCS through analog output ports AO+ and AO-. This acquisition scheme requires an isolator between the motor protector and the DCS system. The current signal acquired by the motor protector needs to be processed by the isolator and the AD conversion module before it can be used by the DCS system. Although this processing scheme is common, it is complex in structure. Especially in large projects with a large number of motors, the disadvantages of the entire processing scheme become more obvious, as follows:

[0028] First, analog signals of 4-20mA can only be wired one-to-one, resulting in a large number of terminal cabinets and isolator cabinets, occupying a large area. If the distance between the power distribution room and the DCS room is long, the amount of cable used is enormous, and the routing is very complex, making it difficult to troubleshoot system problems.

[0029] Secondly, a motor protector requires a signal isolator and an analog input channel. As the number of motor protectors increases, the number of signal isolators and analog input modules will increase, resulting in voltage drop and signal loss in the system.

[0030] Third, analog input modules will occupy space in the DCS cabinet, and the number of DCS cabinets will increase accordingly; in addition, the price of DCS cabinets and signal isolators is relatively expensive, which will lead to a higher overall project cost.

[0031] To address the problem of complex structures in existing data acquisition devices, this utility model provides a data acquisition device for analog quantities of a motor protector and a DCS system.

[0032] like Figure 1 , Figure 2 As shown, the data acquisition device for analog quantities of motor protector and DCS system provided in this embodiment of the invention includes a protector group 1, an analog quantity data acquisition device 2, a switch 3, and a DCS system 4 connected in sequence.

[0033] There are one or more protector groups 1. Each protector group 1 includes multiple motor protectors 11 that use the MODBUS RTU communication protocol and are connected sequentially via serial ports.

[0034] The output of protector group 1 is connected to analog data acquisition device 2.

[0035] Analog data acquisition device 2 is connected to DCS system 4 via switch 3.

[0036] Modbus RTU (Modbus Remote Terminal Unit) is a widely used serial communication protocol in industrial automation. It employs a master-slave structure, where the master device initiates communication and the slave device responds. Modbus RTU communication typically uses RS-232 or RS-485 interfaces for serial communication.

[0037] The motor protector and DCS system analog data acquisition device provided in this embodiment utilize the motor protector's built-in serial port and adopt the MODBUSRTU communication protocol to transmit the acquired motor current signal sequentially to the DCS system through the analog data acquisition unit and switch. This greatly reduces the number of cables, signal isolators, and analog input modules used. At the same time, the overall data acquisition device has a simple circuit, saves space in the DCS cabinet, reduces construction work, and is more economical. It also fully utilizes the data processing capabilities of the DCS system, thereby effectively solving the problem of complex data acquisition device structure.

[0038] Furthermore, within each protector group 1, multiple motor protectors 11 are connected sequentially via a daisy-chain wiring structure.

[0039] Among them, the daisy chain wiring structure can effectively reduce the space required for wiring and can use a single resistor to match the termination, thereby simplifying the wiring complexity.

[0040] In terms of controlling high-order harmonic interference in wiring, daisy-chain wiring structure shows good results and helps to improve the quality and stability of signal transmission.

[0041] The daisy-chain cabling structure is relatively simple, easy to understand and implement, and convenient for management and maintenance.

[0042] Because information can be quickly transferred between devices in a daisy-chain cabling structure, this cabling structure is particularly suitable for rapid coordination and communication in emergency situations.

[0043] Daisy-chain cabling reduces signal reflection and interference, improving signal transmission quality and communication speed. Specifically, in a daisy-chain cabling structure, each device is connected to two adjacent devices during cabling, allowing signals to pass between devices without reflection or interference.

[0044] In a daisy-chain cabling structure, each device has the same cable length, which helps to ensure signal quality and improve communication speed.

[0045] Daisy-chain cabling is easily scalable because new devices can be connected to both ends of existing equipment, making it ideal for expanding large networks.

[0046] Since each device can receive and send information, the system can continue to operate unaffected even if one device fails, thus improving the system's reliability and security.

[0047] As can be seen from the above, the daisy-chain cabling scheme has significant advantages in terms of space occupation, high-order harmonic interference control, structural simplicity, information transmission efficiency, signal quality, cable length consistency, scalability, system reliability and security.

[0048] Furthermore, the serial port of the motor protector 11 is an RS485 interface.

[0049] RS-485 is a differential signal transmission method with long transmission distance and high anti-interference capability.

[0050] In this embodiment, for user convenience, the RS485 interface built into the motor protector 11 is selected.

[0051] Furthermore, the analog data acquisition unit 2, the switch 3, and the DCS system 4 are connected via Ethernet.

[0052] Furthermore, the analog data acquisition device 2 can be configured with a maximum of 254 units.

[0053] Specifically, since each Ethernet segment has 254 addresses, a maximum of 254 analog data acquisition devices can be set up in this scheme.

[0054] Furthermore, analog data acquisition unit 2 is a communication management unit with 8 serial ports;

[0055] Each serial port of the communication management unit is connected in series with 10 motor protectors 11;

[0056] Each motor protector 11 has two RS485 interfaces.

[0057] In this embodiment, since each analog data acquisition device 2 has 8 serial ports, and each serial port can connect 10 motor protectors 11 in series, the communication address of each motor protector 11 connected to each serial port of the analog data acquisition device 2 must be between 1 and 247 and cannot be repeated. The communication baud rate can be 1200, 2400, 4800, 9600, 19200, and 38400.

[0058] Furthermore, the communication management unit is an ANet-2E8S1 intelligent communication management unit.

[0059] Furthermore, the motor protector 11 is an ARD2F intelligent motor protector.

[0060] In this embodiment, each ARD2F smart motor protector has two RS485 serial ports, and each ANet-2E8S1 smart communication manager has eight serial ports. Each serial port of the ANet-2E8S1 smart communication manager can connect up to ten ARD2F smart motor protectors in a daisy-chain configuration. Therefore, each ANet-2E8S1 smart communication manager can connect to 80 ARD2F smart motor protectors. Similarly, as the number of ANet-2E8S1 smart communication managers increases, the number of ARD2F smart motor protectors that can be connected also increases exponentially.

[0061] The electric motor protector and the analog data acquisition device of the DCS system of this utility model adopt the RS485 communication interface built into the electric motor protector and use the MODBUSRTU communication protocol to send the current signal of the motor to the DCS system. The biggest advantage of this scheme is that it uses a one-to-many bus method to connect the communication ports in series. The communication wiring method adopts a daisy chain wiring structure, and then the tail end wire is sent to the analog data acquisition device. Finally, the analog data acquisition device communicates with the DCS system through a switch.

[0062] This solution utilizes the RS485 interface built into the motor protector to acquire signals. It can adopt a one-to-many bus method, which is not only convenient for construction but also saves on cables.

[0063] This solution uses RS485 communication, which can eliminate the need for isolators and analog input modules; moreover, RS485 communication has a longer communication distance and stronger anti-interference capability compared to 4-20mA signals.

[0064] With the reduction of analog cables, the removal of isolators, and the reduction of control modules, the space used in the DCS cabinet is greatly saved, thereby effectively reducing the number of DCS cabinets used.

[0065] The overall solution is simpler and clearer, reducing the amount of system engineering construction, lowering equipment costs, improving quality and efficiency, and facilitating the maintenance of the data acquisition device in the later stages.

[0066] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A data acquisition device for analog quantities in a motor protector and DCS system, characterized in that, include: The protector group (1), analog data acquisition unit (2), switch (3) and DCS system (4) are connected in sequence. The protector group (1) may be one or more; each protector group (1) includes multiple motor protectors (11) that use the MODBUS RTU communication protocol and are connected sequentially via serial ports; The output terminal of the protector group (1) is connected to the analog data acquisition unit (2); The analog data acquisition device (2) is connected to the DCS system (4) through the switch (3).

2. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 1, characterized in that, Within each of the protector groups (1), a plurality of motor protectors (11) are connected in sequence via a daisy-chain wiring structure.

3. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 2, characterized in that, The serial port of the motor protector (11) is an RS485 interface.

4. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 3, characterized in that, The analog data acquisition device (2), the switch (3), and the DCS system (4) are connected via Ethernet.

5. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 4, characterized in that, The analog data acquisition device (2) can be set to a maximum of 254.

6. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 3, characterized in that, The analog data acquisition unit (2) is a communication management unit with 8 serial ports; Each serial port of the communication management machine is connected in series with 10 of the motor protectors (11); Each of the motor protectors (11) has two RS485 interfaces.

7. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 6, characterized in that, The communication management unit is an ANet-2E8S1 intelligent communication management unit.

8. The data acquisition device for analog quantities of the motor protector and DCS system according to claim 6, characterized in that, The motor protector (11) is an ARD2F intelligent motor protector.

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